If the production is led in court and its authenticity is the key to the accused's innocence, yet its authenticity has not been established or disproved by any party, is it reasonable conduct for the trial judge to proceed and come to a ruling without asking that the production be authenticated?

If one party is relying on a production and another party is relying on that same production being disproved as authentic, surely the trial judge, in the name of fairness and justice, should ask that the production is authenticated (which would be the responsibility of the defence in this instance) and if the defence then failed to prove its authenticity the trial judge could advance towards his ruling? Relying on the rule that an accused person need not prove anything unless challenged on a specific point (which would be the case here), if the Crown does not challenge the admissibility of the production or demand that the production is authenticated, surely it is unreasonable for the trial judge to arrive at a ruling which, due to the contents of this particular production, would be an absolute impossibility?